The present invention relates to a disposable syringe in the field of medical apparatus, and in particular to a self-destroying disposable syringe and a self-destroying method thereof.
It is a trend that the disposable syringe is used for substituting the reusable syringe, and there have been various types of disposable syringes. A self-destroying syringe disclosed in Chinese patent application no. 200320110786.X and a self-destroying syringe disclosed in Chinese patent application no. 03266160.6 develop in the aspect of avoiding the reuse of syringe. However, there are still some problems, for example, in the former, the self-destroying characteristic is poor due to only a plug fitting with a plug cavity, while in the latter, the configuration is complex for manufacturing. In another Chinese patent application no. 200420105856.7, another self-destroying disposable syringe as shown in FIG. 1 is disclosed, the syringe comprising a needle base 1, a barrel 2, a pushing stem 3, and a piston 4, wherein the end of the needle base 1 is provided with a dual self-destroying ring, the front end of the pushing stem 3 is provided with a hub for fitting with the piston 4, while the rear end is provided with a pawl for interlocking with a self-locking ring of the barrel 2. Though the syringe with the above structure can achieve the function of self-destroying, there are still some problems: 1. the needle base structure is complex and thus increases the resistance to self-destroy, which affects the self-destroy result; 2. the tip end and the spherical protrusion of the pushing stem 3 are hard for manufacturing; 3. the front end of the pushing stem 3 is provided with a pushing disc for fitting with the barrel 2 and sealed by the piston 4, and during the pushing process, negative pressure and resistance may be generated, which goes against the injection; 4. the piston 4 is of abnormal shape and consequently hard for manufacturing.